1. Field of the Invention
The present invention relates to roller forming machinery of the type in which a flat strip of metal to be formed is passed through a series of tandem aligned rolls that progressively form the final shape. More particularly, the invention relates to a variable width roll forming machine wherein a plurality of roller accepting shafts are journaled to a main block mounted to a fixed base plate, and an equal plurality of axially aligned roller accepting sleeves are journaled for rotation in vertical stands mounted to a movable base plate. As the movable base plate is moved laterally, the sleeves move back and forth over a reduced diameter portion of the roller accepting shafts to vary the width of the roll forming machine. Although this arrangement is advantageous for all types of roll forming production, it is particularly advantageous in a panel roll forming machine where panels of the same type of cross-section can be formed in many different widths simply by moving the base plate of the roll forming machine thus saving costly down time which was necessary with prior art machines.
2. Description of the Prior Art
The roller forming process basically involves taking a coiled flat strip of metal and passing the same through a series of tandem aligned rolls that progressively cold form the final shape. Pre-notching, piercing, embossing, coiling and flying cutoff machines can be incorporated as automatic operations in the roll forming process. The forming rollers of prior art roll forming machines are generally arranged in mating pairs, with the two rollers of each pair configured to produce a predetermined lateral deformation of an elongated metal sheet passed lengthwise between them. Normally, such a machine comprises several pairs of forming rollers, and each pair of rollers takes what is known as a "pass" at the strip of material. The rollers or passes are located at spaced intervals along the path traversed by the workpiece. They cooperate to impart a progressive deformation or bend to the workpiece as it works through successive forming roller pairs along that path. A wide variety of roll formed products in fields such as the automotive, building, furniture, appliance and toy field have made roller forming a very popular and almost essential process in the manufacturing industry today. Although an almost endless variety of profiles can be imparted to workpieces with roller forming machinery, the production of each different profile, and even different widths of the same profile has required, until the time of the present invention, the use of a different set of forming rollers.
Each profile usually requires the presence of several rollers on each of the roller receiving shafts. The two roller shafts for each roller pair usually have their opposite ends journaled in bearings that are either mounted in a main block, or on support stands at each side of the machine. Gears are secured to the roller shafts near their ends adjacent to the main block for drivingly connecting the shafts with a drive means. Thus, the interchange of forming rollers for conversion to production of a different type of workpiece has involved, in prior art machines, the removal and installation of all of the support stands along the side of the machine remote from the main block. This has involved hours of time for each tooling change, with the roller forming machine being out of production during each changeover.
This had led those skilled in the roller forming art to provide a large variety of different solutions to the problems of roll forming machine changeover. Two popular attempts at solving these problems have been the "raft plate" type of roll forming machine and the "turret type" roll forming machine.
U.S. Pat. No. 4,557,129 issued Dec. 10, 1985 to applicant's assignee is an example of the turret type machine. In this type of roll forming machine, a rotatable turret mount assembly is provided to support a plurality of radially extending preset sets of form roll tooling, with each set being adapted for a different form of final product. The turret mount assembly is adapted for selected limited rotation upon a longitudinal axis to rapidly place any one of the plurality of preset sets of tooling in its operational position. Gear means interconnect a transmission means and the forming rolls for rotation thereof in unison. This type of machine is very advantageous in certain production situations but does require the supplying of four sets of roll forming machinery and its related expense.
Another type of turret roller forming machine is shown in U.S. Pat. No. 4,724,695 issued Feb. 16, 1988 to Herbert M. Stoehr. In this case, paired roller carrying shafts of a roller forming machine are arranged in side by side sets on a table normally supported on a fixed base but elevatable for 180.degree. rotation. Thus, either one of the two sets can be in operation coupled to drive heads on the base along one side while the other set is idle. Axially movable clutch members on the drive edge provide for their quick connection to and disconnection from the outboard sets of roller shafts of the set in the operative position. However, this machine also requires a provision of extra sets of roller forming machinery.
An example of the most recent attempt of which applicant is aware to solve this problem is U.S. Pat. No. 4,831,851 issued May 23, 1989 to applicant's assignee. Applicant is a co-inventor of such roll forming machine. The specification of this patent is specifically incorporated herein by reference. Some of the transmission and drive features of such machine are used in the present invention. In this type of roll forming machine, a rafted roll form assembly, including a raft plate and a plurality of vertically aligned, power rotated, longitudinally spaced pairs of complimental rolls are arranged in a set to successively and operatively receive and feed there between elongated strips of stock. A gear train including a plurality of gears and a drive gear interconnect the sets of rolls. In order to change the rafted roll form assembly, including the raft plate and the set of complimental rolls carried by the raft plate to another roll form assembly for making another metal part, a quick disconnect structure is provided which includes a drive clutch on the drive gear of the gear train of the raft assembly. This construction enables one set of forming rollers, or one raft, to be immediately removed from the roll forming machine and replaced by a second raft when it is necessary to change the roll forming operation. This construction solved many problems in the prior art, but did not solve the problem of how to quickly change from making panels of one transverse configuration in several different widths, as there was no easy way to vary the width of the forming rollers on the roll forming machine. This is particularly a problem in making wide, flat, panels having forming substantially only at the edges thereof.